Edwin Smith
410a105184
And, remove the IsLiteral string kind. This removes the hazard of creating a string whose data is freed before the string. Callsites passing in a literal should use StaticString. Everything else can use CopyString or AttachString.
448 linhas
14 KiB
C++
448 linhas
14 KiB
C++
/*
|
|
+----------------------------------------------------------------------+
|
|
| HipHop for PHP |
|
|
+----------------------------------------------------------------------+
|
|
| Copyright (c) 2010- Facebook, Inc. (http://www.facebook.com) |
|
|
+----------------------------------------------------------------------+
|
|
| This source file is subject to version 3.01 of the PHP license, |
|
|
| that is bundled with this package in the file LICENSE, and is |
|
|
| available through the world-wide-web at the following url: |
|
|
| http://www.php.net/license/3_01.txt |
|
|
| If you did not receive a copy of the PHP license and are unable to |
|
|
| obtain it through the world-wide-web, please send a note to |
|
|
| license@php.net so we can mail you a copy immediately. |
|
|
+----------------------------------------------------------------------+
|
|
*/
|
|
|
|
#ifndef incl_HPHP_STRING_DATA_H_
|
|
#define incl_HPHP_STRING_DATA_H_
|
|
|
|
#include <runtime/base/types.h>
|
|
#include <runtime/base/util/countable.h>
|
|
#include <runtime/base/memory/smart_allocator.h>
|
|
#include <runtime/base/macros.h>
|
|
#include <runtime/base/bstring.h>
|
|
#include <util/hash.h>
|
|
#include <util/alloc.h>
|
|
#include <runtime/base/util/exceptions.h>
|
|
|
|
namespace HPHP {
|
|
|
|
class SharedVariant;
|
|
class Array;
|
|
class String;
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
/**
|
|
* A Slice is a compact way to refer to an extent of array elements.
|
|
* This type is designed to be passed around by value. Methods on slice
|
|
* are set up to match the Boost Range<T> concept.
|
|
*/
|
|
template <class T>
|
|
struct Slice {
|
|
T* ptr; // pointer to bytes, not necessarily \0 teriminated
|
|
uint32_t len; // number of bytes, not counting possible \0
|
|
Slice(T* ptr, int len) : ptr(ptr), len(len) {}
|
|
T* begin() const { return ptr; }
|
|
T* end() const { return ptr + len; }
|
|
uint32_t size() const { return len; }
|
|
};
|
|
typedef Slice<const char> StringSlice;
|
|
typedef Slice<char> MutableSlice;
|
|
|
|
// Aggressively copy small strings and free the passed-in buffer immediately;
|
|
// otherwise keep the buffer for long strings, and free it when the string
|
|
// is mutated or released.
|
|
enum AttachStringMode { AttachString };
|
|
|
|
// const char* points to client-owned memory, StringData will copy it
|
|
// at construct-time using smart_malloc. This is only ok when the StringData
|
|
// itself was smart-allocated.
|
|
enum CopyStringMode { CopyString, AttachLiteral = CopyString };
|
|
|
|
// reserve space for buffer that will be filled in by client.
|
|
enum ReserveStringMode { ReserveString };
|
|
|
|
// const char* points to client-owned memory, StringData will copy it
|
|
// at construct-time using malloc. This works for any String but is
|
|
// meant for StringData instances which are not smart-allocated (e.g.
|
|
// live across multiple requests).
|
|
enum CopyMallocMode { CopyMalloc };
|
|
|
|
/**
|
|
* Inner data class for String type. As a coding guideline, String and
|
|
* StringOffset classes should delegate real string work to this class,
|
|
* although both String and StringOffset classes are more than welcome to test
|
|
* nullability to avoid calling this class.
|
|
*
|
|
* A StringData can be in two formats, small or big. Small format
|
|
* stores the string inline by overlapping with some fields, as follows:
|
|
*
|
|
* small: m_data:8, _count:4, m_len:4, m_hash:4,
|
|
* m_small[44]
|
|
* big: m_data:8, _count:4, m_len:4, m_hash:4,
|
|
* junk[12], node:16, shared:8, cap:8
|
|
*
|
|
* If the format is IsShared, we always use the "big" layout.
|
|
* resemblences to fbstring are not accidental.
|
|
*/
|
|
class StringData {
|
|
friend class StackStringData;
|
|
StringData(const StringData&); // disable copying
|
|
StringData& operator=(const StringData&);
|
|
|
|
enum Format {
|
|
IsSmall = 0, // short str overlaps m_big
|
|
IsShared = 0x1000000000000000, // shared memory string
|
|
IsMalloc = 0x2000000000000000, // m_big.data is malloc'd
|
|
IsSmart = 0x3000000000000000, // m_big.data is smart_malloc'd
|
|
IsMask = 0xF000000000000000
|
|
};
|
|
|
|
public:
|
|
const static uint32_t MaxSmallSize = 43;
|
|
|
|
/* max length of a string, not counting the terminal 0. This is
|
|
* MAX_INT-1 to avoid this kind of hazard in client code:
|
|
* int size = string_data->size();
|
|
* ... = size + 1; // oops, wraparound.
|
|
*/
|
|
const static uint32_t MaxSize = 0x7ffffffe; // 2^31-2
|
|
|
|
/**
|
|
* StringData does not formally derive from Countable, however it has a
|
|
* _count field and implements all of the methods from Countable.
|
|
*/
|
|
IMPLEMENT_COUNTABLE_METHODS_NO_STATIC
|
|
|
|
void setRefCount(int32_t n) { _count = n;}
|
|
/* Only call preCompute() and setStatic() in a thread-neutral context! */
|
|
void preCompute() const;
|
|
void setStatic() const;
|
|
bool isStatic() const { return _count == RefCountStaticValue; }
|
|
|
|
/**
|
|
* Get the wrapped SharedVariant.
|
|
*/
|
|
SharedVariant *getSharedVariant() const {
|
|
if (isShared()) return m_big.shared;
|
|
return nullptr;
|
|
}
|
|
|
|
static StringData *Escalate(StringData *in);
|
|
|
|
/**
|
|
* When we have static StringData in SharedStore, we should avoid directly
|
|
* deleting the StringData pointer, but rather call destruct().
|
|
*/
|
|
void destruct() const { if (!isStatic()) delete this; }
|
|
|
|
StringData() : m_data(m_small), _count(0), m_len(0), m_hash(0) {
|
|
m_big.shared = 0;
|
|
m_big.cap = IsSmall;
|
|
m_small[0] = 0;
|
|
}
|
|
|
|
/**
|
|
* Different ways of constructing StringData. Default constructor at above
|
|
* is actually only for SmartAllocator to pre-allocate the objects.
|
|
*/
|
|
explicit StringData(const char* data) {
|
|
initCopy(data);
|
|
}
|
|
StringData(const char *data, AttachStringMode) {
|
|
initAttach(data);
|
|
}
|
|
StringData(const char *data, CopyStringMode) {
|
|
initCopy(data);
|
|
}
|
|
StringData(const char* data, int len, AttachStringMode) {
|
|
initAttach(data, len);
|
|
}
|
|
StringData(const char* data, int len, CopyStringMode) {
|
|
initCopy(data, len);
|
|
}
|
|
StringData(const char* data, int len, CopyMallocMode) {
|
|
initMalloc(data, len);
|
|
}
|
|
StringData(const StringData* s, CopyStringMode) {
|
|
StringSlice r = s->slice();
|
|
initCopy(r.ptr, r.len);
|
|
}
|
|
StringData(StringSlice r1, CopyStringMode) {
|
|
initCopy(r1.ptr, r1.len);
|
|
}
|
|
|
|
// Create a new string by concatingating two existing strings.
|
|
StringData(const StringData* s1, const StringData* s2) {
|
|
initConcat(s1->slice(), s2->slice());
|
|
}
|
|
StringData(const StringData* s1, StringSlice s2) {
|
|
initConcat(s1->slice(), s2);
|
|
}
|
|
StringData(const StringData* s1, const char* lit2) {
|
|
initConcat(s1->slice(), StringSlice(lit2, strlen(lit2)));
|
|
}
|
|
StringData(StringSlice s1, StringSlice s2) {
|
|
initConcat(s1, s2);
|
|
}
|
|
StringData(StringSlice s1, const char* lit2) {
|
|
initConcat(s1, StringSlice(lit2, strlen(lit2)));
|
|
}
|
|
|
|
/**
|
|
* Create a new empty string big enough to hold the requested size,
|
|
* not counting the \0 terminator.
|
|
*/
|
|
explicit StringData(int reserve);
|
|
|
|
explicit StringData(SharedVariant *shared);
|
|
|
|
public:
|
|
void append(StringSlice r) { append(r.ptr, r.len); }
|
|
void append(const char *s, int len);
|
|
static const StringData* convert_double_helper(double n);
|
|
static const StringData* convert_integer_helper(int64_t n);
|
|
StringData *copy(bool sharedMemory = false) const;
|
|
MutableSlice reserve(int capacity);
|
|
MutableSlice mutableSlice() {
|
|
assert(!isImmutable());
|
|
return isSmall() ? MutableSlice(m_small, MaxSmallSize) :
|
|
MutableSlice(m_data, bigCap());
|
|
}
|
|
StringData* shrink(int len); // setSize and maybe realloc
|
|
StringData* setSize(int len) {
|
|
assert(len >= 0 && len <= capacity() && !isImmutable());
|
|
m_data[len] = 0;
|
|
m_len = len;
|
|
m_hash = 0; // invalidate old hash
|
|
return this;
|
|
}
|
|
|
|
~StringData() { checkStack(); releaseData(); }
|
|
void checkStack() {
|
|
/**
|
|
* StringData should not generally be allocated on the
|
|
* stack - because references to it could escape. If
|
|
* you know what you're doing, use StackStringData,
|
|
* which maintains refCounts appropriately, and checks
|
|
* that the StringData didnt escape
|
|
*/
|
|
assert(!m_data ||
|
|
(uintptr_t(this) - Util::s_stackLimit >=
|
|
Util::s_stackSize));
|
|
}
|
|
|
|
/**
|
|
* Informational.
|
|
*/
|
|
const char *data() const {
|
|
// TODO: t1800106: re-enable this assert
|
|
//assert(rawdata()[size()] == 0); // all strings must be null-terminated
|
|
return rawdata();
|
|
}
|
|
// This method should only be used internally by the String class.
|
|
int size() const { return m_len; }
|
|
static uint sizeOffset() { return offsetof(StringData, m_len); }
|
|
int capacity() const { return isSmall() ? MaxSmallSize : bigCap(); }
|
|
StringSlice slice() const {
|
|
return StringSlice(m_data, m_len);
|
|
}
|
|
bool empty() const { return size() == 0;}
|
|
bool isShared() const { return format() == IsShared; }
|
|
bool isSmall() const { return format() == IsSmall; }
|
|
bool isImmutable() const { return isShared() || isStatic(); }
|
|
DataType isNumericWithVal(int64_t &lval, double &dval, int allow_errors) const;
|
|
bool isNumeric() const;
|
|
bool isInteger() const;
|
|
bool isStrictlyInteger(int64_t &res) const {
|
|
if (isStatic() && m_hash < 0) return false;
|
|
StringSlice s = slice();
|
|
return is_strictly_integer(s.ptr, s.len, res);
|
|
}
|
|
bool isZero() const { return size() == 1 && rawdata()[0] == '0'; }
|
|
bool isValidVariableName() const;
|
|
|
|
/**
|
|
* Mutations.
|
|
*/
|
|
StringData *getChar(int offset) const;
|
|
void setChar(int offset, CStrRef substring);
|
|
void setChar(int offset, char ch);
|
|
void inc();
|
|
void negate();
|
|
void set(bool key, CStrRef v) { setChar(key ? 1 : 0, v); }
|
|
void set(char key, CStrRef v) { setChar(key, v); }
|
|
void set(short key, CStrRef v) { setChar(key, v); }
|
|
void set(int key, CStrRef v) { setChar(key, v); }
|
|
void set(int64_t key, CStrRef v) { setChar(key, v); }
|
|
void set(double key, CStrRef v) { setChar((int64_t)key, v); }
|
|
void set(CStrRef key, CStrRef v);
|
|
void set(CVarRef key, CStrRef v);
|
|
|
|
/**
|
|
* Type conversion functions.
|
|
*/
|
|
bool toBoolean() const;
|
|
char toByte (int base = 10) const { return toInt64(base);}
|
|
short toInt16 (int base = 10) const { return toInt64(base);}
|
|
int toInt32 (int base = 10) const { return toInt64(base);}
|
|
int64_t toInt64 (int base = 10) const;
|
|
double toDouble () const;
|
|
DataType toNumeric(int64_t &lval, double &dval) const;
|
|
|
|
strhash_t getPrecomputedHash() const {
|
|
assert(!isShared());
|
|
return m_hash & STRHASH_MASK;
|
|
}
|
|
|
|
strhash_t hash() const {
|
|
strhash_t h = m_hash & STRHASH_MASK;
|
|
return h ? h : hashHelper();
|
|
}
|
|
|
|
/**
|
|
* Comparisons.
|
|
*/
|
|
bool equal(const StringData *s) const {
|
|
assert(s);
|
|
if (s == this) return true;
|
|
int ret;
|
|
|
|
if (!(m_hash < 0 || s->m_hash < 0)) {
|
|
ret = numericCompare(s);
|
|
if (ret >= -1) {
|
|
return ret == 0;
|
|
}
|
|
}
|
|
if (m_len != s->m_len) return false;
|
|
ret = memcmp(rawdata(), s->rawdata(), m_len);
|
|
return ret == 0;
|
|
}
|
|
|
|
bool same(const StringData *s) const {
|
|
assert(s);
|
|
if (m_len != s->m_len) return false;
|
|
return !memcmp(rawdata(), s->rawdata(), m_len);
|
|
}
|
|
|
|
bool isame(const StringData *s) const {
|
|
assert(s);
|
|
if (m_len != s->m_len) return false;
|
|
return bstrcaseeq(rawdata(), s->rawdata(), m_len);
|
|
}
|
|
|
|
int compare(const StringData *v2) const;
|
|
|
|
/**
|
|
* Memory allocator methods.
|
|
*/
|
|
DECLARE_SMART_ALLOCATION(StringData);
|
|
void dump() const;
|
|
std::string toCPPString() const;
|
|
static void sweepAll();
|
|
|
|
static StringData *FindStaticString(const StringData* str);
|
|
static StringData *GetStaticString(const StringData* str);
|
|
static StringData *GetStaticString(const std::string& str);
|
|
static StringData *GetStaticString(const String& str);
|
|
static StringData *GetStaticString(const char* str);
|
|
static StringData *GetStaticString(char c);
|
|
static size_t GetStaticStringCount();
|
|
static uint32_t GetCnsHandle(const StringData* cnsName);
|
|
static uint32_t DefCnsHandle(const StringData* cnsName, bool persistent);
|
|
static Array GetConstants();
|
|
/**
|
|
* The order of the data members is significant. The _count field must
|
|
* be exactly FAST_REFCOUNT_OFFSET bytes from the beginning of the object.
|
|
*/
|
|
private:
|
|
union {
|
|
const char* m_cdata;
|
|
char* m_data;
|
|
};
|
|
protected:
|
|
mutable int32_t _count;
|
|
private:
|
|
// m_len and m_data are not overlapped with small strings because
|
|
// they are accessed so frequently that even the inline branch to
|
|
// measurably slows things down. Its worse for m_len than m_data.
|
|
// If frequent callers are refacotred to use slice() then we could
|
|
// revisit this decision.
|
|
uint32_t m_len;
|
|
mutable strhash_t m_hash; // precompute hash codes for static strings
|
|
union __attribute__((__packed__)) {
|
|
char m_small[MaxSmallSize + 1];
|
|
struct __attribute__((__packed__)) {
|
|
// Calculate padding so that node, shared, and cap are pointer aligned,
|
|
// and ensure cap overlaps the last byte of m_small.
|
|
static const size_t kPadding = sizeof(m_small) -
|
|
sizeof(SweepNode) - sizeof(SharedVariant*) - sizeof(uint64_t);
|
|
char junk[kPadding];
|
|
SweepNode node;
|
|
SharedVariant *shared;
|
|
uint64_t cap;
|
|
} m_big;
|
|
};
|
|
|
|
private:
|
|
/**
|
|
* Helpers.
|
|
*/
|
|
void initAttach(const char* data);
|
|
void initCopy(const char* data);
|
|
void initAttach(const char* data, int len);
|
|
void initCopy(const char* data, int len);
|
|
void initMalloc(const char* data, int len);
|
|
void initConcat(StringSlice r1, StringSlice r2);
|
|
void releaseData();
|
|
int numericCompare(const StringData *v2) const;
|
|
MutableSlice escalate(uint32_t cap); // change to smart-malloced string
|
|
void enlist();
|
|
void delist();
|
|
|
|
strhash_t hashHelper() const NEVER_INLINE;
|
|
|
|
bool checkSane() const;
|
|
const char* rawdata() const { return m_data; }
|
|
Format format() const {
|
|
return Format(m_big.cap & IsMask);
|
|
}
|
|
int bigCap() const {
|
|
assert(!isSmall());
|
|
return m_big.cap & ~IsMask;
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Use this class to declare a StringData on the stack
|
|
* It will verify that the StringData does not escape.
|
|
*/
|
|
class StackStringData : public StringData {
|
|
public:
|
|
StackStringData() { incRefCount(); }
|
|
explicit StackStringData(const char* s) : StringData(s) { incRefCount(); }
|
|
template <class T>
|
|
StackStringData(const char* s, T p) : StringData(s, p) { incRefCount(); }
|
|
template <class T>
|
|
StackStringData(const char* s, int len, T p) :
|
|
StringData(s, len, p) { incRefCount(); }
|
|
|
|
~StackStringData() {
|
|
// verify that no references escaped
|
|
assert(!decRefCount());
|
|
releaseData();
|
|
m_data = 0;
|
|
m_big.cap = IsSmall;
|
|
}
|
|
};
|
|
|
|
ALWAYS_INLINE inline void decRefStr(StringData* s) {
|
|
if (s->decRefCount() == 0) s->release();
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
}
|
|
|
|
#endif // incl_HPHP_STRING_DATA_H_
|